Use and misuse of equipment for dental local analgesia.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to C Russell.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Quantitative and qualitative examination of anaerobically isolated flora of the gingival crevice and saliva was carried out. It was found that half the organisms were anaerobes and that there were twice as many gram-positive organisms as there were gram-negative ones. Rods were predominant in the gingival crevice (60.5%) and cocci in saliva (69.1%). Of the total organisms, nonsporing, gram-positive anaerobic rods accounted for 24% in the gingival crevice and 9.7% in saliva. These organisms were characterized on the basis of the type of fatty acids produced from glucose and various biochemical reactions. They belonged to the following genera: Actinomyces, Propionibacterium, Arachnia, Lactobacillus, Eubacterium, and Bifidobacterium. Bifidobacteria were present only in saliva. Although members of the other genera were present both in the gingival crevice and saliva, there were considerable differences in the proportion of any particular organism (in relation to the total anaerobic viable count) between the two sites. The result of this study also indicates a greater than previously appreciated level of Propionibacterium and Arachnia in the human mouth.
Actinomyces viscosus, growing on a tooth in the presence of sucrose, slowly produced a loosely-attached plaque, the pH being 6.1 after 120 h. When the tooth was inoculated simultaneously with A. viscosus and either Streptococcus sanguis or Streptococcus mutans, firmly-adherent plaque was quickly formed and the pH fell below 5 after 33 h with the former Streptococcus and 24 h with the latter. A. viscosus disappeared from each mixed plaque by 120 h.
Explore the source record for details and available documents.
Rats given tetracycline in their drinking water for one week were orally inoculated with Candida albicans in the following week. Colonization of the mouth by the fungus resulted, whether the rats continued to receive tetracycline or not, over a period of 22 weeks. Histological changes indicative of oral candidosis were also found both in rats maintained on tetracycline throughout the experiment and in animals given the drug only initially. It is suggested that exposure to tetracycline as tested in this experiment causes a lasting reduction in the rat's ability to expel C. albicans, or an enhancement of the organism's colonizing propensities.
Viridans streptococci isolated in apparently pure culture from periapical dental abscess have been examined. It has been found that each abscesses is associated with only one type of a given species of Streptococcus. The distribution of types of Strep. mitis found in abscesses differed from the distribution in healthy mouths, but no particular type occurred significantly more often in abscesses than in mouths.
Explore the source record for details and available documents.
Sterilisation of teeth for homogenous transplantation has been successfully achieved by combined ultrasonic waves and immersion in 6 per cent hydrogen peroxide. This combined treatment was found to have no harmful effect on the tooth integrity as indicated by enamel solubility, hardness, root canal seal and tooth size and weight. It is suggested the method offers the possibility of storing teeth in a "tooth bank".
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The effect of chlorhexidine on the development of plaque, resulting from the inoculation with saliva of a tooth mounted in an artificial mouth, has been studied. The agent delayed the formation of plaque and also inhibited changes in pH and Eh, whether sucrose was present or not. Applied as a rinse at intervals of 12 h it prevented formation of plaque and pH and Eh remained constant. Moreover, chlorhexidine inhibited pH and Eh changes in established plaque. A single application of a gel containing chlorhexidine also greatly inhibited plaque development.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Long-term candidal infection of the rat's tongue has been found to produce marked epithelial hyperplasia with keratin trapped between the folds of hyperplastic epithelium. The epithelium showed atypia which did not amount to carcinoma in situ. Degenerative changes were found in the superficial layers of the lingual muscle beneath areas of candidal infection, and after a year, hyalinized fibrous tissue appeared to replace the damaged muscle.
Apparatus which enables the simultaneous continuous monitoring of pH and Eh of bacterial dental plaque as it develops on a tooth surface in an artificial mouth is described. Details of the electrodes used, monitoring equipment, and culture conditions are given. Preliminary results are given showing the Eh and pH values of plaque produced in vitro to be in close agreement with readings reported for plaque in vivo. The effect of the incorporation of 1 per cent sucrose in the medium on these parameters is reported and a distinct inverse relationship between pH and Eh recorded.